From who?

SK hynix, Samsung and Micron are all eager to squeeze Apple for the market price of DDR5. They won't build extra fab capacity for them because Nvidia, AMD and OpenAI will outbid them for future capacity. Products like HBM are overbooked right now too, which means that building an extra DDR5 facility might just end up feeding the enterprise HBM market.

And CXMT has refused Apple's business entirely: https://appleinsider.com/articles/26/08/06/chinese-ram-suppl...